However, when
technology evolves from Release 6 High Speed
Packet Access (HSPA) with single-input multiple-
output (SIMO) 1 ¥ 2 to Release 7 with 64
quadrature amplitude modulation (QAM) and 2
¥ 2 multiple-input multiple-output (MIMO), the
system only experiences a modest 10–20 percent
improvement in the aggregate system throughput